Redox Isomerization/(3+2) Allenoate Annulation by Auto?Tandem Phosphine Catalysis

A phosphine-catalyzed approach to pyrrolines has been developed that involves two mechanistically unlinked catalytic processes. The first the redox isomerization of amino crotonates provide access aliphatic tosyl imines, which then engage in a (3+2) annulation with various allenoates. reaction shows generality, 24 examples established, along low yielding and moderately enantioselective variant. Mechanistic studies indicate viability process is linked selection catalysts similar propensity add coupling partners.